1. Technical Field
The present invention relates to a piezoelectric element and a method for manufacturing the same, and to a piezoelectric actuator, a liquid ejecting head and a liquid ejecting apparatus.
2. Related Art
It is known that piezoelectric elements are used in liquid ejecting heads of liquid ejecting apparatuses, such as ink jet printers used for, for example, image recording apparatuses and display manufacturing apparatuses, and in various types of piezoelectric actuator.
A piezoelectric element may be manufactured by, for example, forming a piezoelectric layer on a lower electrode, and covering the piezoelectric layer with an upper electrode.
For example, in JP-A-2006-269958, it is disclosed that the piezoelectricity of the piezoelectric layer is enhanced by forming the electroconductive uppermost layer of the lower electrode, which comes into contact with the piezoelectric layer, of a material containing lanthanum nickelate so as to control the orientation of the piezoelectric layer.
However, when such a piezoelectric element is operated, stress is liable to concentrate at the edge of the lower electrode. In addition, while the piezoelectricity of the piezoelectric layer on the lanthanum nickelate layer is enhanced, lanthanum nickelate is diffused into the piezoelectric layer to reduce the withstand voltage.
Consequently, the piezoelectric layer of the piezoelectric element may be broken, for example, with a crack or burnout in a vicinity of the ends of the lower electrode. Accordingly, it is desirable to provide a piezoelectric element that is not easily broken physically and is thus highly reliable.